In one proposed structure of a power output apparatus, an engine and a first motor generator are connected to an output shaft via a planetary gear mechanism, a second motor generator is connected to the output shaft via a transmission, and a battery is arranged to receive and transmit electric power from and to the first motor generator and the second motor generator (see, for example, Japanese Patent Laid-Open Gazette No. 2004-204960). This proposed power output apparatus adequately corrects and updates an output torque of the second motor generator to compensate for a decrease in output torque to the output shaft during a changeover of a gear ratio in the transmission.